Selected Anniversaries:
- December 3, 1973 - Pioneer program: Pioneer 10 sends back the first close-up images of Jupiter.
- December 4, 1959 - A monkey returns to Earth safely, after being launched 55 miles high into outer space by the United States space program.
- December 6, 1957 - Project Vanguard: A launchpad explosion of Vanguard TV3 thwarts the first United States attempt to launch a satellite into orbit around the Earth.
- December 6, 2006 - NASA reveals photographs taken by Mars Global Surveyor suggesting the presence of liquid water on Mars.
- December 7, 1972 - Apollo 17, the last Apollo moon mission, is launched. The crew take the photograph known as "The Blue Marble" as they leave the Earth.
- December 14, 1962 - NASA's Mariner 2 becomes the first spacecraft to fly by Venus.
- December 18, 1973 - Soviet Soyuz Programme: Soyuz 13, crewed by cosmonauts Valentin Lebedev and Pyotr Klimuk, is launched from Baikonur in the Soviet Union.
Others:
- December 1, 1987 - NASA announces the names of four companies who were awarded contracts to help build Space Station Freedom.
- December 2, 1993 - Space Shuttle program: STS-61 - NASA launches the Space Shuttle Endeavour on a mission to repair the Hubble Space Telescope.
- December 3, 1999 - NASA loses radio contact with the Mars Polar Lander moments before the spacecraft enters the Martian atmosphere.
- December 7, 1995 - The Galileo spacecraft arrives at Jupiter, a little more than six years after it was launched by Space Shuttle Atlantis during Mission STS-34.
- December 9, 2006 - Shuttle Discovery launches on the STS-116 mission at 8:45 P.M., the first night launch in 4 years (STS-113 being the last).
- December 10, 1963 - The United States Air Force's X-20 Dyna-Soar spaceplane program is cancelled by Robert McNamara.
- December 11, 1972 - Apollo 17 becomes the sixth mission to land on the Moon.
- December 15, 1965 - Gemini program: Gemini 6A, crewed by Wally Schirra and Thomas Stafford, is launched from Cape Kennedy, Florida.
- December 18, 1999 - NASA launches into orbit the Terra platform carrying five Earth Observation instruments, including ASTER, CERES, MISR, MODIS and MOPITT.
- December 19, 1972 - Project Apollo: The last manned lunar flight, Apollo 17, crewed by Eugene Cernan, Ron Evans and Harrison Schmitt, returns to Earth.
- December 21, 1968 - Project Apollo: Apollo 8, crewed by Frank Borman, Jim Lovell and William Anders, is launched from the Kennedy Space Center in Florida.
- December 24, 1968 - The crew of Apollo 8 enter into orbit around the Moon, becoming the first humans to do so.
- December 25, 2003 - The ill-fated Beagle 2 probe which was released from the Mars Express Spacecraft on December 19, disappears shortly before its scheduled landing.
- December 26, 1973 - Soyuz 13 lands on earth after a week in orbit.
- December 26, 1974 - Salyut 4 is launched.
- December 25, 2004 - Cassini orbiter releases Huygens probe which successfully landed on Saturn's moon, Titan on January 14, 2005.